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E46 (1999 - 2006) The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

I've only seen and experienced the single 3" exhaust. Maybe you can dig around a bit and find some info on a single 2-3/4" exhaust. Back pressure would be ever so slightly higher, but again, the single 3" exhaust has proven to consistently give around 6 WHP gains.

The G-Power supercharger kit can be had for $2,100 from Schmiedmann (link here). That does NOT include an intercooler, an oil cooler, or installation (assuming you're not doing it yourself).

once the project goes live, i'll check whether it is better to go 3'' or the next smaller size.
one thing though i'm not sure of, would keeping my twin-piped rear stock muffler cause any restrictions or is it better to change it to a single piped muffler?

Quote:

Originally Posted by MalibuMafiaV

If you really want turbo. I'd suggest building your own turbo kit with a ko3 or ko4 turbo off an Audi. Go to a machine shop and get a custom built exhaust manifold after you size everything out yourself. That way you can mount the turbo properly etc. The Ko3 and ko4 turbos are cheap and easy to find. You can honestly build yourself a turbo kit for about $2500 with ALL parts and labor NOT including the tune. The tune would probably cost about $500-1000 all in all. Not to bad but is it worth it?. That's what you have to ask yourself. And this is keeping the same compression on your engine so you'd only be able to do like 6psi safely with it unless you dropped the compression a bit.

Quote:

Originally Posted by nivo

Read my site, and do not buy that kit, the turbo alone will most likely last like 100-300 miles before the seals go.

the manifold you can buy for $140, the piping for $100-$200 the rest is up to you.